Magnetic core and coil device

ABSTRACT

There is disclosed a magnetic core and coil device having a strip which interfits with the flanges of adjacent ends of primary and secondary coil bobbins so to retain it in position to receive terminals to which wires leading to and from the coils may be connected.

United States Patent [191 Long 1 July 22, 1975 [$4] MAGNETIC CORE AND con. DEVICE 3.436.709 4/1969 Schepirs et 1|. 336/l92 [75] Inventor: Clifton W. Lang, San Marcos. Tex.

['73] Assignee: Esquire, Inc., New York, N.Y. Primary Examm" 1-hm" J Kozma 22 m 7, 1974 Attorney, Agent, or Firm-W. F. l-lyer; Marvin B.

Eickenroht [21] Appl. NO.: SIZJZZ 52 us. or. ass/mo; ass/m; 336/198 ABSTRACT Ink H /10 There is disclosed a magnetic core and coil device FRI! 01 flh 1 1 I92. having a strip which interfite with the flanges of adja- 335/193, cent ends of primary and secondary coil bobbins so to retain it in position to receive terminals to which wires Relflflncfl leading to and from the coils may be connected.

UNITED SWES'PATENTS 2,249,051 7/l94l Suhl 336/l92 4 4 Film MAGNETIC CORE AND COIL DEVICE This invention relates generally to a magnetic core and coil device for use in a ballasts, transformers or like equipment. More particularly, it relates to improvements in a device of this type wherein bobbins about which a pair of coils are wound are disposed about the middle leg and on opposite sides of shunts extending between the middle leg and each side leg of the core.

In the assembly of devices of this type, the bobbins are disposed about the middle leg of the core, preparatory to welding the side and end legs thereof to the middle leg. The shunts may comprise parts of the middle leg or the side legs, or parts which are separate from both the middle and side legs. For example, the core may be an EIE type in which segments of both the end legs and shunts are formed on the side legs. Alternatively, it may be a Cross type, wherein the shunts are formed on the middle leg, and the side and end legs form a solid loop, or a T and L type, wherein segments of the end legs are formed on both the middle and side legs, and the shunts are formed by parts separate from both.

In any event, in using such a device, its necessary to connect the ends of wires from its coils to the ends of wires leading to and from the device as well as to one another. To facilitate this, the ends of the start and finish wires of the coils may be attached to individual parts mounted on the flange of each bobbin. However, this not only requires the separate attachment of each such part by soldering, crimping, or the like, but also that the wires be extended from the individual parts to connection with a terminal strip at some other location.

An object of this invention is to provide a device of this type having a strip which may be mounted between the flanges of the adjacent ends of the bobbins, and thus in a position to receive terminals to which the wire ends may be connected, in a simple and expeditious manner, and, more particularly, without the need for soldering, crimping, or otherwise attaching it to the flanges and/or coils.

These and other objects are accomplished in accordance with the illustrated embodiment of the present invention, by a magnetic core and coil device of the type described having a terminal strip which is retained in a position extending between the flanges on adjacent ends of the bobbins by means of interfitting parts on the strip and flanges. These parts extend essentially parallel to the axis of the middle leg of the core, so as to permit them to be moved into interfitting relation as the bobbins are moved over the middle leg with the strip held between them. At least in those devices having the EIE and T and L laminations, wherein the shunts are separate from the middle leg, the terminal strip also serves to space the flanges from one another to permit shunts to be moved therebetween in assembling the side and end legs of the core about the bobbins.

In the illustrated and preferred embodiment of the device, the interfitting parts comprise tabs on the strip adapted to be received closely within slots in the flanges. As a result, the bobbins may be of conventional construction which require no special preparation other than formation of the slots in their flanges. More particularly, these slots open to the ends of the flanges, and the tabs comprise enlargements on opposite ends of the strip.

In the drawings, etc.

FIG. 1 is a perspective view of a device constructed in accordance with this invention, with the wiring removed therefrom for illustrating purposes;

FIG. 2 is a diagrammatic, exploded view of the device;

FIG. 3 is an enlarged, perspective view of the portion of the device during assembly of the bobbins and terminal strip on the middle leg of the core; and

FIG. 4 is an enlarged, side view of the assembled device, showing the manner in which the ends of its wires are attached to terminals on the strip.

With reference now to the details of the abovedescribed drawings, the overall device, which is indicated in its entirety by reference character 20, is shown in FIG. 1 to comprise a magnetic core 21 and a primary and secondary coils 22? and 228. As best illustrated in FIG. 2, the core is of the EIE type having a middle leg 23 and side legs 24 each having inwardly extending segments 25 and 26 at its upper and lower ends for connection to the middle leg to form the upper and lower legs of the core, and an inwardly extending segment 27 vertically intermediate the segments 25 and 26 for extension to a position close to the middle leg to form the shunts of the core. As previously described, each of the primary and secondary coils 22? and 225 is disposed about the middle leg 23 within the side legs and vertically intermediate the shunt and one of the upper or lower legs of the core.

As well known in the art, each of coils 22? and 228 comprises a bobbin or spool 28? and 288, respectively, about which electrical wiring is wound, each coil having an opening of substantially the same size and configuration as the middle leg 23 of the core for sliding closely thereover. The coils are of such height that flanges 29 and 30 on their upper and lower ends are next to the adjacent sides of the end legs and shunts of the core. As shown, the outer edges of the flanges extend beyond the wiring wound on each of the coils. Also as well known in the art, each leg of the core is made up of laminated plates of magnetic material adapted to cooperate with the wiring of the coils in a well known manner.

As shown, the upper and lower end of middle leg 23 of the core extend beyond the upper and lower ends of coils, so that, with the coils assembled thereon, leg segments 25 and 26 may be welded to the opposite side faces of the middle leg. When the leg segments have been so welded, the inner ends of the shunt segments 27 will be disposed close to but spaced from adjacent opposite sides of the middle leg 23 of the core.

As shown in FIG. 4, the ends of start wire 32, finish wire 33 and tap wire 39 extend from the primary coil 22P near the flange 30 thereof. Also, the ends of start and finish wires 34 and 35, respectively, extend from the secondary coil 228 near the flange 29 thereof. As also shown, flange 30 of the primary coil is recessed at 36 to receive the end of start wire 32, and the flange 29 of the secondary coil is recessed at 37 to receive the end of start wire 34.

The terminal strip, which is indicated in its entirety by reference character 40, is formed from a relatively thin sheet of plastic or other electrically nonconductive material. It includes a midsection 41 which extends for .a length somewhat less than that of the flanges 29 and 30, and which is of a height at least equal to that of shunt segments 27, so that, during assembly of the device, and as will be described to follow,

the strip holds the flanges 29 and 30 is spaced relation to receive the shunt segments therebetween.

The terminal strip also includes enlargements 42 on each end of midsection 41, which provide a pair of upwardly and downwardly extending tabs, and the flanges on adjacent ends of the coils are provided with slots 43 and 44 to receive the tabs and thereby retain the strip between the flanges. More particularly, as best shown in FIG. 3, slots 43 are formed in the ends of the flange 30 on the primary coil 22F to receive the upwardly extending tabs on the strip, and slots 44 are formed in the ends of the flange 29 on the secondary coil 225 to receive the downwardly extending tabs of the strip. As can be seen from FIG. 3, the slots in each flange are spaced from one another a distance just slightly greater than the length of midsection 41 of the terminal strip, so that the tabs are retained not only against movement toward or away from the coils, but also against lateral movement in a direction perpendicular to the axis of the coils.

Thus, as previously mentioned, the terminal strip is mounted in retained position between the coils merely upon movement of the coils axially toward one another with the strip 40 held in its upright position between them. Preferably, the coils are so moved as they are being assembled over the middle leg 23 of the core. That is, primary coil 22? is first moved over the leg 23, the retainer strip 40 is then mounted on the flange 30 of the primary coil by fitting its upwardly extending tabs into the slots 43, and the secondary coil is then moved over the free end of the leg 23 until its slots 44 fit over the downwardly extending tabs of strip 40. As previously mentioned, since height of midsection 41 of the strip is at least equal to that of the shunts segments, it spaces the flanges 29 and 30 to receive the shunt segments as the legs 24 are moved sideways into position about the coils preparatory to welding their segments 25, 26 and 27 to the sides of middle leg 23.

The upper and lower edges of the midsection 41 of strip 40 are recessed at 45 and 46, respectively, so that with the strip in retained position between the flanges of the coils, the recess 45 extends from the right edge of flange recess 36 to the left thereof, and the recess 46 extends from the lefthand edge of the flange recess 37 to the right thereof. During assembly of the coils and retainer strip in the manner previously described, the start wire 32 and tap wire 39 of the primary coil are pulled to the side thereof and through the recess 36 in the flange and the recess 45 in the terminal strip so as to dispose their ends on the front or outer side of the terminal strip, as shown in FIG. 4. Prior to movement of the secondary coil into interfitting relation with the terminal strip, the ends of its start and finish wires 34 and 35, respectively, are pulled to one side thereof through the recess 37, and thus in position to extend through the recess 46 in the top edge of strip midsection 41, whereby such ends are also disposed on the front side of the strip 40.

The strip is provided with a series of holes 47 which are adapted to receive strip terminals 48 when the device has been assembled in the manner described. As shown in H0. 4, the ends of the terminals are inserted into the holes 47 from the front side of the strip so a to provide means to which wire ends may be connected. Thus, in a device which is wired for use in a typical ballast transformer, the end of finish wire 33 of the primary coil is connected to the terminal in the leftmost hole, the end of start wire 32 is connected to the left intermediate terminal, and the end of tap wire 39 is connected to the right intermediate terminal. Also, the end of start wire 34 of the secondary coil is connected to the rightmost terminal, and the end of finish wire 35 thereof is connected to the right intermediate terminal, and thus to the tap wire 39 of the primary coil.

The terminals also provide means to which insulated wire 50 leading from line voltage, 51 from a common line, and 52 leading to the load may be connected. Thus, wire 50 is connected to the leftmost terminal and thus to finish wire 33 of the primary coil, wire 51 is connected to the left intermediate terminal and thus to start wire 32 of the primary coil, and wire 52 is connected to the rightmost terminal and thus to start wire 34 of the secondary coil.

Since insulated wires 50, 51 and 52 are adapted to extend to and connect with other parts remote from the device, they may be bent at rather severe angles with respect to the front side of the terminal strip 40. To relieve stresses in the wires resulting from such bending, slots 53 are formed in the ends of the terminal strip enlargements 42, each to receive one or more of the insulated wires, as illustrated in FIG. 4.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the apparatus.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the present invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed 1. A device, comprising a magnetic core having side legs, a middle leg intermediate the side legs, end legs connecting the ends of the side and middle legs, and shunts extending between the middle leg and each side leg intermediate the end legs, a pair of coils each wound about a bobbin which is disposed about the middle leg of the core on opposite sides of the shunts, the bobbins having flanges on their adjacent ends, and a terminal strip extending between the flanges, each flange and the strip having parts which interfit to retain said strip in position between said flanges, said interfitting parts extending essentially parallel to axis of the middle leg of the core so as to be moveable into interfitting relation as the bobbins are assembled over the middle leg of the core.

2. A device of the character defined in claim 1, wherein the interfitting parts on flanges comprise slots, and the interfitting parts on the strip comprises tabs adapted to be closely received in the slots.

3. A device of the character defined in claim 2, wherein said slots extend inwardly from the ends of :flCh flange, and said tabs comprise enlargements on ,=osite ends of the strip.

# A device of the character defined in claim 3,

wnerein said tabs have slots opening extending inwardly from the ends thereof to receive wires therein. i l 

1. A device, comprising a magnetic core having side legs, a middle leg intermediate the side legs, end legs connecting the ends of the side and middle legs, and shunts extending between the middle leg and each side leg intermediate the end legs, a pair of coils each wound about a bobbin which is disposed about the middle leg of the core on opposite sides of the shunts, the bobbins having flanges on their adjacent ends, and a terminal strip extending between the flanges, each flange and the strip having parts which interfit to retain said strip in position between said flanges, said interfitting parts extending essentially parallel to axis of the middle leg of the core so as to be moveable into interfitting relation as the bobbins are assembled over the middle leg of the core.
 2. A device of the character defined in claim 1, wherein the interfitting parts on flanges comprise slots, and the interfitting parts on the strip comprises tabs adapted to be closely received in the slots.
 3. A device of the character defined in claim 2, wherein said slots extend inwardly from the ends of each flange, and said tabs comprise enlargements on opposite ends of the strip.
 4. A device of the character defined in claim 3, wherein said tabs have slots opening extending inwardly from the ends thereof to receive wires therein. 